Semiconductor device

ABSTRACT

A semiconductor device includes first and second active regions parallel to each other and respectively extending in a first direction, an isolation layer between the first and second active regions, a first line structure and a second line structure overlapping the first and second active regions and the isolation layer, parallel to each other, and extending in a second direction, a first source/drain region on the first active region, and a second source/drain region on the second active region. The first line structure includes a first gate structure, a second gate structure, and a first insulating separation pattern between the first and second gate structures. The second line structure includes a third gate structure, a fourth gate structure, and a second insulating separation pattern between the third and fourth gate structures. The first and second insulating separation patterns are spaced apart from each other. The first insulating separation pattern has first and second side surfaces opposing each other, and third and fourth side surfaces opposing each other. At least one of the first and second side surfaces and at least one of the third and fourth side surfaces have different side profiles.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to Korean Patent Application No. 10-2021-0080703 filed on Jun. 22, 2021 in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

The present disclosure relates to a semiconductor device.

As demand for high performance, high speed, and/or multifunctionality in semiconductor devices increases, the degree of integration of semiconductor devices is increasing. In manufacturing a semiconductor device having a fine pattern corresponding to the trend for high integration in a semiconductor device, it is necessary to implement patterns having a fine width or a fine separation distance.

SUMMARY

One or more example embodiments provide a semiconductor device having an improved degree of integration.

In accordance with an aspect of an example embodiment, a semiconductor device includes a substrate; a first active region and a second active region extending parallel to each other in a first direction, on the substrate; an isolation layer disposed between the first active region and the second active region; a line structure disposed on the substrate, overlapping the first and second active regions and the isolation layer, and extending in a second direction that is perpendicular to the first direction; a first source/drain region disposed on the first active region; a second source/drain region disposed on the second active region; a common contact plug disposed on a first side of the line structure, contacting the first source/drain region and the second source/drain region, and overlapping the isolation layer; and an interlayer insulating layer disposed on a second side of the line structure, on the isolation layer, wherein the line structure is disposed on the isolation layer and between the common contact plug and the interlayer insulating layer, the line structure includes a first gate structure overlapping the first active region and extending on the isolation layer, a second gate structure overlapping the second active region and extending on the isolation layer, and an insulating separation pattern disposed between the first gate structure and the second gate structure and extending into the isolation layer, at least a portion of the insulating separation pattern is disposed between the common contact plug and the interlayer insulating layer, the insulating separation pattern has a first side surface and a second side surface opposing each other in the first direction, and a third side surface and a fourth side surface opposing each other in the second direction, at least one of the first side surface and the second side surface of the insulating separation pattern includes a first portion, a second portion on a level lower than the first portion, and a third portion on a level lower than the second portion, and a slope of each of the first portion and the third portion is steeper than a slope of the second portion.

In accordance with an aspect of an example embodiment, a semiconductor device includes a substrate; a first active region and a second active region extending parallel to each other in a first direction, on the substrate; an isolation layer disposed between the first active region and the second active region; a first line structure and a second line structure overlapping the first and second active regions and the isolation layer, and extending parallel to each other in a second direction that is perpendicular to the first direction, on the substrate; a first source/drain region disposed on the first active region; and a second source/drain region disposed on the second active region, wherein the first line structure includes: a first gate structure overlapping the first active region and extending on the isolation layer, a second gate structure overlapping the second active region and extending on the isolation layer, and a first insulating separation pattern disposed between the first gate structure and the second gate structure and extending into the isolation layer, the second line structure includes: a third gate structure overlapping the first active region and extending on the isolation layer, a fourth gate structure overlapping the second active region and extending on the isolation layer, and a second insulating separation pattern disposed between the third gate structure and the fourth gate structure and extending into the isolation layer, the first insulating separation pattern and the second insulating separation pattern are spaced apart from each other, the first insulating separation pattern has a first side surface and a second side surface opposing each other in the first direction, and a third side surface and a fourth side surface opposing each other in the second direction, and at least one of the first side surface and the second side surface of the first insulating separation pattern and at least one of the third side surface and the fourth side surface of the first insulating separation pattern have different side profiles.

In accordance with an aspect of an example embodiment, a semiconductor device includes a substrate; a first active region and a second active region extending parallel to each other in a first direction, on the substrate; an isolation layer disposed between the first active region and the second active region; a plurality of line structures disposed on the substrate, overlapping the first and second active regions and the isolation layer, extending parallel to each other in a second direction perpendicular to the first direction, and spaced apart from each other; a first source/drain region disposed on the first active region; a second source/drain region disposed on the second active region; interlayer insulating layers disposed between adjacent line structures of the plurality of line structures; and a common contact plug, wherein the plurality of line structures includes a first line structure and a second line structure adjacent to each other and spaced apart from each other, the first line structure includes: a first gate structure overlapping the first active region and extending on the isolation layer, a second gate structure overlapping the second active region and extending on the isolation layer, and a first insulating separation pattern disposed between the first gate structure and the second gate structure and extending into the isolation layer, the second line structure includes: a third gate structure overlapping the first active region and extending on the isolation layer, a fourth gate structure overlapping the second active region and extending on the isolation layer, and a second insulating separation pattern disposed between the third gate structure and the fourth gate structure and extending into the isolation layer, the common contact plug includes a portion contacting the first and second source/drain regions and disposed between the first insulating separation pattern and the second insulating separation pattern, the first insulating separation pattern includes a first side surface and a second side surface opposing each other in the first direction, and a third side surface and a fourth side surface opposing each other in the second direction, the first side surface of the first insulating separation pattern includes a first portion, a second portion below the first portion and a third portion below the second portion, the third portion contacts with the isolation layer, the second portion is bent and extended from the first portion in a direction away from a central axis of the first insulating separation pattern, and the first portion is bent and extended from the second portion.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the present disclosure will be more apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIGS. 1 and 2A to 2E are diagrams illustrating a semiconductor device according to an example embodiment;

FIG. 3 is a cross-sectional view illustrating a modified example of a semiconductor device according to an example embodiment;

FIG. 4 is a cross-sectional view illustrating a modified example of a semiconductor device according to an example embodiment;

FIGS. 5A and 5B are views illustrating a modified example of a semiconductor device according to an example embodiment;

FIGS. 6A and 6B are views illustrating a modified example of a semiconductor device according to an example embodiment;

FIG. 7A is a cross-sectional view illustrating a modified example of a semiconductor device according to an example embodiment;

FIG. 7B is a cross-sectional view illustrating a modified example of a semiconductor device according to an example embodiment;

FIG. 7C is a cross-sectional view illustrating a modified example of a semiconductor device according to an example embodiment;

FIG. 8A is a plan view illustrating a modified example of a semiconductor device according to an example embodiment;

FIG. 8B is a plan view illustrating a modified example of a semiconductor device according to an example embodiment;

FIG. 8C is a plan view illustrating a modified example of a semiconductor device according to an example embodiment;

FIG. 9 is a cross-sectional view illustrating a modified example of a semiconductor device according to an example embodiment; and

FIGS. 10 to 19D are diagrams illustrating an example of a method of forming a semiconductor device according to an example embodiment.

DETAILED DESCRIPTION

First, an example of a semiconductor device according to an example embodiment will be described with reference to FIG. 1 and FIGS. 2A to 2E. In FIGS. 1 and 2A to 2E, FIG. 1 is a plan view illustrating a semiconductor device according to an example embodiment, FIG. 2A is a cross-sectional view illustrating a region taken along line I-I′ of FIG. 1 , FIG. 2B is a cross-sectional view taken along the line II-II′ of FIG. 1 , FIG. 2C is a cross-sectional view taken along the line of FIG. 1 , FIG. 2D is a cross-sectional view taken along line IV-IV′ of FIG. 1 , and FIG. 2E is a cross-sectional view taken along line V-V′ of FIG. 1 .

Referring to FIGS. 1 and 2A to 2E, a semiconductor device 1 according to an example embodiment may include a substrate 3, active regions 6 a and 6 b, an isolation layer 15, source/drain regions 28 a, 28 b, 28 c, 28 d, 28 e and 28 f, line structures, contact plugs 65 a, 65 b, 65 c, 65 d, and 65 e, and interlayer insulating layers 36.

The substrate 3 may include a semiconductor material, for example, a group IV semiconductor, a group III-V compound semiconductor, or a group II-VI compound semiconductor. For example, the group IV semiconductor may include silicon, germanium, or silicon-germanium.

Each of the active regions 6 a and 6 b may protrude from the substrate 3 in a vertical direction Z perpendicular to the upper surface of the substrate 3. The active regions 6 a and 6 b may include a first active region 6 a and a second active region 6 b parallel to and adjacent to each other. Each of the first and second active regions 6 a and 6 b may have a line shape or a bar shape extending in a first direction (X). The first direction X may be a direction parallel to the upper surface of the substrate 3.

The first active region 6 a and the second active region 6 b may have different conductivity types. When the first active region 6 a has a first conductivity type, the second active region 6 b may have a second conductivity type, different from the first conductivity type. The first conductivity type may be an N-type conductivity type, and the second conductivity type may be a P-type conductivity type. In another example, the first conductivity type may be a P-type conductivity type, and the second conductivity type may be an N-type conductivity type. In this case, the ‘conductivity type’ may mean a conductivity type formed by doping a semiconductor material with impurities, for example, an N-type semiconductor or a P-type semiconductor.

The isolation layer 15 may include a first device isolation layer 15 a, a second device isolation layer 15 b, and a third device isolation layer 15 c. The first device isolation layer 15 a may be disposed between the first active region 6 a and the second active region 6 b. The first active region 6 a may be disposed between the first device isolation layer 15 a and the second device isolation layer 15 b. The second active region 6 b may be disposed between the first device isolation layer 15 a and the third device isolation layer 15 c. At least a portion of the isolation layer 15 may have an upper surface at a lower level than upper surfaces of the first and second active regions 6 a and 6 b as shown, for example, in FIGS. 2C, 2D, and 2E.

The semiconductor device 1 may further include first channel layers 12 a stacked while being spaced apart from each other in the vertical direction Z, on the first active region 6 a, and second channel layers 12 b stacked while being spaced apart from each other in the vertical direction Z, on the second active region 6 b.

The line structures may include a first line structure (42 a, 60 a, 42 b) and a second line structure (42 c, 60 b, 42 d) parallel to and adjacent to each other, and a third line structure 40 a and a fourth line structure 40 b disposed on either side of the first and second line structures. The line structures may extend in a second direction (Y) perpendicular to the first direction (X).

The first line structure (42 a, 60 a, 42 b) may include a first gate structure 42 a overlapping the first active region 6 a and extending onto the isolation layer 15, a second gate structure 42 b overlapping the second active region 6 b and extending onto the isolation layer 15, and a first insulating separation pattern 60 a disposed between the first gate structure 42 a and the second gate structure 42 b and extending into the first device isolation layer 15 a. The second line structure (42 c, 60 b, 42 d) may include a third gate structure 42 c overlapping the first active region 6 a and extending onto the device isolation layer 15, a second gate structure 42 d overlapping the second active region 6 b and extending onto the isolation layer 15, and a second insulating separation pattern 60 b disposed between the third gate structure 42 c and the fourth gate structure 42 d and extending into the first device isolation layer 15 a.

The first gate structure 42 a may include a first gate pattern 45 a, a first gate spacer 25 a 1 and a second gate spacer 25 a 2 disposed on either side of the first gate pattern 45 a, and a first insulating capping pattern 48 a on the first gate pattern 45 a and the first and second gate spacers 25 a 1 and 25 a 2.

The second gate structure 42 b may include a second gate pattern 45 b, a third gate spacer 25 b 1 and a fourth gate spacer 25 b 2 disposed on either side of the second gate pattern 45 b, and a second insulating capping pattern 48 b on the second gate pattern 45 b and the third and fourth gate spacers 25 b 1 and 25 b 2.

The third gate structure 42 c may include a third gate pattern 45 c, a fifth gate spacer 25 c 1 and a sixth gate spacer 25 c 2 disposed on either side of the third gate pattern 45 c, and a third insulating capping pattern 48 c on the third gate pattern 45 c and the fifth and sixth gate spacers 25 c 1 and 25 c 2.

The fourth gate structure 42 d may include a fourth gate pattern 45 d, a seventh gate spacer 25 d 1 and an eighth gate spacer 25 d 2 disposed on either side of the fourth gate pattern 45 d, and a fourth insulating capping pattern 48 d on the fourth gate pattern 45 d and the seventh and eighth gate spacers 25 d 1 and 25 d 2.

Each of the third and fourth line structures 40 a and 40 b may include a fifth gate pattern 45, ninth gate spacers 25 disposed on both sides of the fifth gate pattern 45, and a fifth insulating capping pattern 48 on the fifth gate pattern 45 and the ninth gate spacers 25.

Each of the gate patterns 45 a-45 d and 45 may include a gate dielectric layer 47 and a gate electrode 49 on the gate dielectric layer 47. The gate dielectric layer 47 may include an oxide, nitride, or high-k dielectric material. The high-k dielectric material may refer to a dielectric material having a higher dielectric constant than that of a silicon oxide layer (SiO₂). The high-k dielectric material may be any one of, for example, aluminum oxide (Al₂O₃), tantalum oxide (Ta₂O₃), titanium oxide (TiO₂), yttrium oxide (Y₂O₃), zirconium oxide (ZrO₂), zirconium silicon oxide (ZrSi_(x)O_(y)), hafnium oxide (HfO₂), hafnium silicon oxide (HfSi_(x)O_(y)), lanthanum oxide (La₂O₃), lanthanum aluminum oxide (LaAl_(x)O_(y)), lanthanum hafnium oxide (LaHf_(x)O_(y)), hafnium aluminum oxide (HfAl_(x)O_(y)), and praseodymium oxide (Pr₂O₃). In some embodiments, the gate dielectric layer 47 may be formed of a multilayer film. A material type of the gate electrode 49 may vary according to transistor regions of the semiconductor device 1. The gate electrode 49 may include a metal nitride such as titanium nitride (TiN), tantalum nitride (TaN), or tungsten nitride (WN), and/or a metallic material such as aluminum (Al), tungsten (W), or molybdenum (Mo), or a semiconductor material such as doped polysilicon. According to example embodiments, the gate electrode 49 may be formed of two or more layers. A material type of the gate electrode 49 may vary according to transistor regions of the semiconductor device 1.

The gate spacers 25 a 1, 25 a 2, 25 b 1, 25 b 2, 25 c 1, 25 c 2, 25 d 1, 25 d 2, and 25 may include an insulating material, for example, at least one of SiO, SiN, SiCN, SiOC, SiON, and SiOCN. The insulating capping patterns 48 a, 48 b, 48 c, 48 d, and 48 may include silicon nitride or a silicon nitride-based insulating material.

The source/drain regions 28 a, 28 b, 28 c, 28 d, 28 e, and 28 f may include source/drain regions 28 a, 28 c and 28 e disposed on the first active region 6 a and having the second conductivity type, and source/drain regions 28 b, 28 d, and 28 f disposed on the second active region 6 b and having the first conductivity type.

When viewed in a plan view, the source/drain regions 28 a, 28 b, 28 c, 28 d, 28 e, and 28 f may include a first source/drain region 28 a disposed between the first gate pattern 45 a and the third gate pattern 45 c, a second source/drain region 28 b disposed between the second gate pattern 45 b and the fourth gate pattern 45 d, a third source/drain region 28 c disposed between the first line structure 40 a and the first gate pattern 45 a, a fourth source/drain region 28 d disposed between the first line structure 40 a and the second gate pattern 45 b, a fifth source/drain region 28 e disposed between the second line structure 40 b and the third gate pattern 45 c, and a sixth source/drain region 28 f disposed between the second line structure 40 b and the fourth gate pattern 45 d.

In the semiconductor device 1, an area in which the first active region 6 a, the first, third and fifth source/drain regions 28 a, 28 c and 28 e having the second conductivity type, and the first and third gate structures 42 a and 42 c are placed may be defined as a first transistor region TR1, and an area in which the second active region 6 b, the second, fourth and sixth source/drain regions 28 b, 28 d and 28 f having the first conductivity type, and the second and fourth gate structures 42 b and 42 d are disposed may be defined as a second transistor region TR2 as shown, e.g., in FIG. 1 . One of the first and second transistor regions TR1 and TR2 may be an NMOS transistor region, and the other may be a PMOS transistor region.

In the first transistor region TR1, each of the first and third gate patterns 45 a and 45 c may extend in the second direction Y while surrounding the first channel layers 12 a on the first active region 6 a. In the second transistor region TR2, each of the second and fourth gate patterns 45 b and 45 d may extend in the second direction Y while surrounding the second channel layers 12 b on the second active region 6 b. The first and second transistor regions TR1 and TR2 may include a multi-bridge channel FET (MBCFET™) transistor that is a gate-all-around type field effect transistor.

Although the number of the first channel layers 12 a stacked while being spaced apart from each other in the vertical direction Z is illustrated as three in the drawings, embodiments are not limited thereto, and the number may be four or more.

Although the number of the second channel layers 12 b stacked while being spaced apart from each other in the vertical direction Z is illustrated as three in the drawings, embodiments are not limited thereto, and the number may be four or more.

The interlayer insulating layers 36 may be disposed between the line structures. For example, the interlayer insulating layers 36 may be disposed between the first line structures 42 a, 60 a, and 42 b and the second line structures 42 c, 60 b, and 42 d, and between the first line structures 42 a, 60 a, and 42 b and the third line structure 40 a, and between the second line structures 42 c, 60 b, and 42 d and the fourth line structure 40 b.

The contact plugs 65 a, 65 b, 65 c, 65 d and 65 e may pass through the interlayer insulating layers 36. The contact plugs 65 a, 65 b, 65 c, 65 d, and 65 e may include a common contact plug 65 a disposed on the first and second source/drain regions 28 a and 28 b and the first device isolation layer 15 a and in contact with the first and second source/drain regions 28 a and 28 b, a first contact plug 65 b on the third source/drain region 28 c and in contact with the third source/drain region 28 c, a second contact plug 65 c on the fourth source/drain region 28 d and in contact with the fourth source/drain region 28 d, a third contact plug 65 d on the fifth source/drain region 28 e and in contact with the fifth source/drain region 28 e, and a fourth contact plug 65 d disposed on the sixth source/drain region 28 f and in contact with the sixth source/drain region 28 f.

The common contact plug 65 a may include a portion extending into the isolation layer 15. A lowermost end of the common contact plug 65 a may be disposed on a level lower than an upper surface of each of the first and second active regions 6 a and 6 b.

Each of the contact plugs 65 a, 65 b, 65 c, 65 d and 65 e may include a plug layer 69, a barrier layer 68 covering side surfaces and a bottom surface of the plug layer 69, and a metal-semiconductor compound layer 67 between the barrier layer 68 and the source/drain regions 28 a, 28 b, 28 c, 28 d, 28 e, and 28 f In some embodiments, in each of the contact plugs 65 a, 65 b, 65 c, 65 d and 65 e, the plug layer 69 and the metal-semiconductor compound layer 67 may directly contact each other. The plug layer 69 may include a metal material such as tungsten or molybdenum, and the barrier layer 68 may include a metal nitride such as titanium nitride (TiN), tantalum nitride (TaN), or tungsten nitride (WN). The metal-semiconductor compound layer 37 may include, for example, metal silicide, metal germanide, or metal silicide-germanide. In the metal-semiconductor compound layer 37, the metal may be titanium (Ti), nickel (Ni), tantalum (Ta), cobalt (Co), or tungsten (W), and the semiconductor may be silicon (Si), germanium (Ge) or silicon germanium (SiGe). For example, the metal-semiconductor compound layer 37 may include at least one of cobalt silicide (CoSi), titanium silicide (TiSi), nickel silicide (NiSi), and tungsten silicide (WSi).

The semiconductor device 1 may further include an insulating liner 33 covering a lower surface of the interlayer insulating layers 36 as shown, e.g., in FIGS. 2D and 2E. The interlayer insulating layers 36 may be formed of silicon oxide or a low dielectric material, and the insulating liner 33 may be formed of a material different from that of the interlayer insulating layers 36, for example, formed of a silicon nitride or silicon nitride-based insulating material. The insulating liner 33 is disposed between the isolation layer 15 and the interlayer insulating layers 36 and may extend to surfaces of the source/drain regions that do not contact the contact plugs. In addition, the insulating liner 33 may extend onto side surfaces of the line structures.

The first and second insulating separation patterns 60 a and 60 b will be described again. The first and second insulating separation patterns 60 a and 60 b may be formed to have the same shape and structure as each other. Accordingly, the description will be focused on the first insulating separation pattern 60 a.

At least a portion of the first insulating separation pattern 60 a may be disposed between the common contact plug 65 a and the interlayer insulating layer 36. In this case, the interlayer insulating layer 36 may be an interlayer insulating layer positioned between the first line structures 42 a, 60 a, and 42 b and the third line structures 40 a.

The first insulating separation pattern 60 a may have a first side surface 60 s 1 and a second side surface 60 s 2 opposing each other, and a third side surface 60 s 3 and a fourth side surface 60 s 4 opposing each other. The first side surface 60 s 1 and the second side surface 60 s 2 may be sequentially disposed in the first direction X, and the third side surface 60 s 3 and the fourth side surface 60 s 4 may be sequentially disposed in the second direction Y.

At least one of the first and second side surfaces 60 s 1 and 60 s 2 and at least one of the third and fourth side surfaces 60 s 3 and 60 s 4 may have different side profiles. For example, at least one of the third and fourth side surfaces 60 s 3 and 60 s 4 may have a substantially vertical side surface.

At least one of the first and second side surfaces 60 s 1 and 60 s 2 may include a first portion 60 s 1 a, 60 s 2 a, a second portion 60 s 1 b, 60 s 2 b at a lower level than the first portion 60 s 1 a, 60 s 1 b, and a third portion 60 s 1 c, 60 s 2 c having a lower level than the second portion 60 s 1 b and 60 s 2 b. For example, the first side surface 60 s 1 may include a first portion 60 s 1 a, a second portion 60 s 1 b, and a third portion 60 s 1 c. In the first side surface 60 s 1, the first and third portions 60 s 1 a and 60 s 1 c may each have a steeper slope than that of the second portion 60 s 1 b. In the first side surface 60 s 1, the third portion 60 s 1 c may be disposed in the first device isolation layer 15 a, the second portion 60 s 1 b may extend from the third portion 60 s 1 c and may have a gentler slope than the third portion 60 s 1 c, and the first portion 60 s 1 a may extend from the second portion 60 s 1 b and have a steeper slope than the second portion 60 s 1 b. See, e.g., FIG. 2B.

In the first side surface 60 s 1, the third portion 60 s 1 c may be in contact with the first device isolation layer 15 a, the second portion 60 s 1 b may be bent and extended from the third portion 60 s 1 c in a direction away from the central axis of the first insulating separation pattern 60 a, and the first portion 60 s 1 a may be bent and extended from the second portion 60 s 1 b.

In the first direction (X), the first insulating separation pattern 60 a may have a first width portion having a substantially constant first width, a second width portion disposed below the first width portion and having a width that is less than the first width and decreases in width, and a third width portion disposed below the second width portion and having a width less than that of the second width portion. In addition, in the first side surface 60 s 1, the first portion 60 s 1 a may be a side surface of the first width portion, the second portion 60 s 1 b may be a side surface of the second width portion, and the third portion 60 s 1 c may be a side surface of the third width portion.

The first line structure (42 a, 60 a, 42 b) may further include a connection spacer 25 ib extending from the first gate spacer 25 a 1 and the third gate spacer 25 b 1, and a connection spacer 25 ia extending from the second gate spacer 25 a 2 and the fourth gate spacer 25 b 2 (see, e.g., FIG. 2B).

Upper ends of the connection spacers 25 ia and 25 ib may be disposed on a level lower than upper surfaces of the first and second gate spacers 25 a 1 and 25 a 2. Upper ends of the connection spacers 25 ia and 25 ib may contact the first and second side surfaces 60 s 1 and 60 s 2 of the first insulating separation pattern 60 a. For example, upper ends of the connection spacers 25 ia and 25 ib may be in contact with the second portions 60 s 1 b and 60 s 2 b of the first and second side surfaces 60 s 1 and 60 s 2 of the first insulating separation pattern 60 a.

Next, various modifications of the semiconductor device 1 according to an example embodiment described above will be described. Hereinafter, in describing various modified examples of the above-described semiconductor device 1, the components that are deformed or replaced among the components of the above-described semiconductor device 1 will be mainly described, and a description of the components substantially the same as those of the above description or a description of the components that may be easily understood from the descriptions or drawings described above will be omitted.

First, various modifications of the semiconductor device 1 according to an example embodiment described above will be described with reference to FIGS. 3 to 7C, respectively. FIGS. 3 to 7C are cross-sectional views illustrating various modified examples of the semiconductor device 1 according to an example embodiment described above.

In a modified example, referring to FIG. 3 , the connection spacers (25 ia and 25 ib in FIG. 2B) are omitted, and the first and second gate spacers 25 a 1 and 25 a 2 may be spaced apart from the third and fourth gate spacers 25 b 1 and 25 b 2. In at least one of the first and second side surfaces 60 s 1 and 60 s 2 described above, the second portions 60 s 1 b and 60 s 2 b (see FIG. 2B) may be replaced by second portions 60 s 1 b′ and 60 s 2 b′ to be in contact with the first device isolation layer 15 a, and accordingly, may have a step-like structure in a region in contact with the first device isolation layer 15 a in the first insulating separation pattern 60 a.

In a modified example, referring to FIG. 4 , a lower end 65 a_C′ of the common contact plug 65 a positioned between the first and second insulating separation patterns 60 a and 60 b may be positioned on a level lower than a lower end of each of the first and second insulating separation patterns 60 a and 60 b.

In a modified example, referring to FIGS. 5A and 5B, the common contact plug 65 a may be replaced with a common contact plug 165 a having a lower surface 165 a_C disposed at a higher level than an upper surface of the first device isolation layer 15 a. The lower surface 165 a_C of the common contact plug 165 a may be disposed on a level lower than the upper surface of the first and second active regions 6 a and 6 b. The insulating liner 33 and the interlayer insulating layer 36 may be disposed between the lower surface 165 a_C of the common contact plug 165 a and the first device isolation layer 15 a.

In a modified example, referring to FIGS. 6A and 6B, the common contact plug 65 a may be replaced with the common contact plug 265 a having a lower surface 265 a_C that is disposed on a level higher than the upper surface of the first device isolation layer 15 a and upper surfaces of the first and second active regions 6 a and 6 b.

In a modified example, referring to FIG. 7A, in the second direction Y, the common contact plug (see 65 a of FIG. 2D) in FIG. 2D may be replaced with a common contact plug 365 a extending from a portion covering the first source/drain region 28 a in a direction away from the second source/drain region 28 b and extending from a portion covering the second source/drain region 28 b in a direction away from the first source/drain region 28 a. In the second direction Y, the common contact plug 365 a may include an end portion extending into the second device isolation layer 15 b and an end portion extending into the third device isolation layer 15 c.

In the second direction Y, lower ends 365 a_E of both end portions of the common contact plug 365 a and a lower end 365 a_C3 of an intermediate portion of the common contact plug 365 a may be disposed in the isolation layer 15.

In a modified example, referring to FIG. 7B, in the second direction Y, the common contact plug (165 a of FIG. 5A) in FIG. 5A may be replaced with a common contact plug 465 a extending from a portion covering the first source/drain region 28 a in a direction away from the second source/drain region 28 b and extending from a portion covering the second source/drain region 28 b in a direction away from the first source/drain region 28 a. In the second direction Y, the common contact plug 465 a may include an end portion overlapping the second device isolation layer 15 b and an end portion overlapping the third device isolation layer 15 c when viewed in the direction Z.

In the second direction Y, lower ends 465 a_E of both end portions of the common contact plug 465 a and a lower end 465 a_C3 of an intermediate portion of the common contact plug 465 a may be spaced apart from the isolation layer 15, and may be disposed on a level lower than the upper surfaces of the first and second active regions 6 a and 6 b.

In a modified example, referring to FIG. 7C, in the second direction Y, the common contact plug (265 a of FIG. 6A) in FIG. 6A may be replaced with a common contact plug 565 a extending from a portion covering the first source/drain region 28 a in a direction away from the second source/drain region 28 b and extending from a portion covering the second source/drain region 28 b in a direction away from the first source/drain region 28 a. In the second direction Y, the common contact plug 565 a may include an end portion overlapping the second device isolation layer 15 b and an end portion overlapping the third device isolation layer 15 c when viewed in the direction Z.

In the second direction Y, lower ends 565 a_E of both end portions of the common contact plug 565 a and a lower end 565 a_C3 of an intermediate portion of the common contact plug 565 a may be spaced apart from the isolation layer 15, and may be disposed on a level higher than the upper surfaces of the first and second active regions 6 a and 6 b.

Next, in the semiconductor device 1 according to an example embodiment described above with reference to FIGS. 8A to 8C, various examples of planar shape of the first and second insulating separation patterns 60 a and 60 b and the common contact plug 65 a will be described.

Referring to FIG. 8A, the common contact plug 665 a may have a bar or line shape extending in the second direction Y, and may have side surfaces 65 a_S1 and 65 a_S2 opposing each other along a longitudinal length of the common contact plug 665 a in the second direction Y. The side surfaces 65 a_S1 and 65 a_S2 may have a straight shape extending in the second direction Y.

In a modified example, referring to FIG. 8B, the common contact plug 765 a may have a bar or line shape extending in the second direction Y, and may have side surfaces 765 a_S1 and 765 a_S2 opposing each other in the longitudinal direction. The side surfaces 765 a_S1 and 765 a_S2 may have recess regions 765 a_S1 a and 765 a_S2 a having a concave shape between the first and second insulating separation patterns 60 a and 60 b. Accordingly, the common contact plug 765 a may have a smaller width between the first and second insulating separation patterns 60 a and 60 b than at other portions of the common contact plug 765 a.

In a modified example, referring to FIG. 8C, the common contact plug 865 a may have a bar or line shape extending in the second direction Y, and may have side surfaces 865 a_S1 and 865 a_S2 opposing each other in the longitudinal direction. The side surfaces 865 a_S1 and 865 a_S2 may have recess regions 865 a_S1 a and 865 a_S2 a having a concave shape between the first and second insulating separation patterns 60 a and 60 b, and may have an asymmetric structure.

Next, a modified example of the common contact plug in the semiconductor device 1 according to an example embodiment described above will be described with reference to FIG. 9 .

In a modified example, referring to FIG. 9 , an intermediate region of the lower surface 965 a_C of the common contact plug 965 a positioned between the first and second active regions 6 a and 6 b or between the first source/drain regions 28 a and 28 b may have a convex shape protruding away from the substrate 3 in a vertical direction Z. For example, the common contact plug 965 a may have a lower surface having a recessed area. The shape of the lower surface 965 a_C may be applied to all of the contact plugs described above.

Next, referring to FIGS. 10 to 19D, an illustrative example of a method of forming a semiconductor device according to an example embodiment will be described. FIGS. 10 to 19D are diagrams illustrating an example of a method of forming a semiconductor device according to an example embodiment. In FIGS. 10 to 19D, FIGS. 10, 14, 16 and 18 are plan views sequentially illustrating a method of forming a semiconductor device according to an example embodiment, FIGS. 11A, 12A, 13A, 15A, 17A, and 19A are cross-sectional views illustrating regions taken along line I-I′ of FIGS. 1, 10, 14, 16 and 18 , FIGS. 11B, 12B, 13B, 15B, 17B and 19B are cross-sectional views illustrating regions taken along line II-II′ of FIGS. 1, 10, 14, 16 and 18 , FIGS. 11C, 13C, 15C and 19C are cross-sectional views illustrating regions taken along line of FIGS. 1, 10, 14, 16 and 18 , and FIGS. 11D, 12B, 13D, 17C and 19D are cross-sectional views illustrating regions taken along line IV-IV′ of FIGS. 1, 10, 14, 16 and 18 .

Referring to FIGS. 10, 11A, 11B, 11C, and 11D, first active structures 6 a, 9 a, 12 a and second active structures 6 b, 9 b, and 12 b may be formed on a substrate 3.

The first active structures 6 a, 9 a, and 12 a may include a first active region 6 a. First sacrificial layers 9 a and first channel layers 12 a may be alternately stacked on the first active region 6 a. The second active structures 6 b, 9 b, and 12 b may include a second active region 6 b. Second sacrificial layers 9 b and second channel layers 12 b may be alternately stacked on the second active region 6 b.

Forming the first active structures 6 a, 9 a, 12 a and the second active structures 6 b, 9 b and 12 b may include forming sacrificial layers and channel layers alternately stacked on a semiconductor substrate, and etching the alternately stacked sacrificial layers and channel layers, and the semiconductor substrate to form a trench defining the first active structures 6 a, 9 a and 12 a and the second active structures 6 b, 9 b, and 12 b.

The substrate 3 may be formed by etching the semiconductor substrate. The substrate 3 may be formed of a semiconductor material, for example, silicon or a compound semiconductor. The first and second active regions 6 a and 6 b may have a shape protruding from the substrate 3 in the vertical direction Z, and may be formed of the same semiconductor material as the substrate 3.

The sacrificial layers 9 a and 9 b and the channel layers 12 a and 12 b may be formed of semiconductor materials by an epitaxial growth process. The sacrificial layers 9 a and 9 b may be formed of a material having etch selectivity with respect to the channel layers 12 a and 12 b. The channel layers 12 a and 12 b may be formed of a first semiconductor material, for example, silicon, and the sacrificial layers 9 a and 9 b may be formed of a second semiconductor material different from the first semiconductor material, for example, formed of at least one material among silicon germanium (SiGe) and germanium (Ge). The first semiconductor material is not limited to silicon, and may be formed of a compound semiconductor different from the second semiconductor material, for example, silicon carbide.

The first active region 6 a and the second active region 6 b may have different conductivity types. The first channel layers 12 a may have a conductivity type different from that of the second channel layers 12 b. The first active region 6 a and the first channel layers 12 a may have the same conductivity type, and the second active region 6 b and the second channel layers 12 b may have the same conductivity type. When the first active region 6 a and the first channel layers 12 a have a first conductivity type, the second active region 6 b and the second channel layers 12 b may have a second conductivity type different form the first conductivity type. The first conductivity type may be an N-type conductivity type, and the second conductivity type may be a P-type conductivity type. In another example, the first conductivity type may be a P-type conductivity type, and the second conductivity type may be an N-type conductivity type.

The number of layers of the channel layers 12 a and 12 b alternately stacked with the sacrificial layers 9 a and 9 b may be variously changed in some embodiments. For example, the channel layers 12 a and 12 b are illustrated as three layers in the drawings, but may also be formed of four or more layers according to example embodiments.

An isolation layer 15 may be formed to cover side surfaces of some of the first active structures 6 a, 9 a, and 12 a and the second active structures 6 b, 9 b, and 12 b, on the substrate 3. The isolation layer 15 may have an upper surface disposed on a level lower than that of the sacrificial layers 9 a and 9 b and the channel layers 12 a and 12 b. The isolation layer 15 may include silicon oxide. The isolation layer 15 may include a first device isolation layer 15 a, a second device isolation layer 15 b, and a third device isolation layer 15 c. The first device isolation layer 15 a may be disposed between the first active region 6 a and the second active region 6 b. The first active region 6 a may be disposed between the first device isolation layer 15 a and the second device isolation layer 15 b. The second active region 6 b may be disposed between the first device isolation layer 15 a and the third device isolation layer 15 c.

The first active structures 6 a, 9 a, and 12 a and the second active structures 6 b, 9 b, and 12 b may be parallel to each other. Each of the first active structures 6 a, 9 a, and 12 a and the second active structures 6 b, 9 b, and 12 b may have a line shape extending in the first direction X.

Preliminary line structures 18 a, 18 b, 18 c, and 18 d may be formed to traverse the first active structures 6 a, 9 a and 12 a and the second active structures 6 b, 9 b and 12 b to be parallel to each other. Each of the preliminary line structures 18 a, 18 b, 18 c, and 18 d may have a line shape extending in the second direction Y.

The preliminary line structures 18 a, 18 b, 18 c, and 18 d may include a first preliminary line structure 18 a and a second preliminary line structure 18 b parallel to each other and adjacent to each other, and a third preliminary line structure 18 c and a fourth preliminary line structure 18 d disposed on both sides of the first and second preliminary line structures 18 a and 18 b. The first and second preliminary line structures 18 a and 18 b may be disposed between the third preliminary line structure 18 c and the fourth preliminary line structure 18 d.

Each of the preliminary line structures 18 a, 18 b, 18 c, and 18 d may include a sacrificial gate 20 and a sacrificial mask 22 sequentially stacked, and gate spacers 25 covering side surfaces of the sequentially stacked sacrificial gate 20 and sacrificial mask 22.

The sacrificial gate 20 may be formed of a silicon oxide layer and a polysilicon layer sequentially stacked. The sacrificial mask 22 may include silicon oxide and/or silicon nitride. The gate spacers 25 may include an insulating material, for example, at least one of SiO, SiN, SiCN, SiOC, SiON, and SiOCN.

Referring to FIGS. 10, 12A, and 12B, using the preliminary line structures 18 a, 18 b, 18 c, 18 d as an etch mask, the first sacrificial layers 9 a and the first channel layers 12 a are etched to expose the first active region 6 a having the first conductivity type, perform epitaxial growth from the first active region 6 a, and form source/drain regions 28 a, 28 c and 28 e having the second conductivity type.

The second sacrificial layers 9 b and the first channel layers 12 b are etched using the preliminary line structures 18 a, 18 b, 18 c, and 18 d as an etch mask, to expose the second active region 6 b, perform epitaxial grown from the second active region 6 b having the second conductivity type, and form source/drain regions 28 b, 28 d, and 28 f having the first conductivity type.

The source/drain regions 28 a, 28 c, 28 e having the second conductivity type and the source/drain regions 28 b, 28 d, 28 f having the first conductivity type may be formed in different process operations.

Referring to FIGS. 10, 13A, 13B, 13C and 13D, an insulating liner 33 and an interlayer insulating layer 36 are sequentially formed, and a planarization process is performed until sacrificial gates 20 are exposed. Accordingly, the sacrificial mask 22 may be removed by the planarization process. The interlayer insulating layer 36 may be formed of silicon oxide or a low dielectric material, and the insulating liner 33 may be formed of a material different from that of the interlayer insulating layer 36, for example, a silicon nitride or silicon nitride-based insulating material.

Referring to FIGS. 14, 15A, 15B and 15C, the sacrificial gates 20 are selectively removed to expose the sacrificial layers 9 a and 9 b, and the sacrificial layers 9 a and 9 b are selectively removed, and gate patterns 45 may be formed in spaces from which the sacrificial gates 20 and the sacrificial layers 9 a and 9 b have been removed. Subsequently, the gate patterns 45 and the gate spacers 25 are partially etched to lower the height of the upper surface, and gate capping patterns 48 may be formed in the space formed as the upper surfaces of the gate patterns 45 and the gate spacers 25 are lowered. The gate capping patterns 48 may be formed of silicon nitride or a silicon nitride-based insulating material.

Each of the gate patterns 45 may include a gate dielectric layer 47 and a gate electrode 49 disposed on the gate dielectric layer 47. The gate patterns 45 may extend to surround the channel layers 12 a and 12 b.

The first and second preliminary line structures 18 a and 18 b described above may be formed of first and second preliminary line structures 38 a and 38 b including the gate pattern 45 instead of the sacrificial gate 20 and the sacrificial mask 22. The third and fourth preliminary line structures 18 c and 18 d described above may be formed of third and fourth line structures 40 a and 40 b including the gate pattern 45, respectively. Accordingly, each of the first and second preliminary line structures 38 a and 38 b and each of the third and fourth line structures 40 a and 40 b may include the gate pattern 45, the gate spacers 25 covering both sides of the gate pattern 45, and a gate capping pattern 48 on the gate pattern 45 and the gate spacers 25.

Referring to FIGS. 16, 17A, 17B, and 17C, first mask patterns 51 may be formed. The first mask patterns 51 may be disposed on the interlayer insulating layers 36, and may each have a line shape extending in the second direction Y.

At least one of the first mask patterns 51 may have a line shape in which a width is narrowed in a boundary region between the first transistor region TR1 and the second transistor region TR2. For example, when viewed in a plan view (see, e.g., FIG. 16 ), portions of at least one of the first mask patterns 51, overlapping the first active region 6 a and the second active region 6 b, respectively, may have a first width, and a portion thereof between the first active region 6 a and the second active region 6 b may have a second width less than the first width.

In a plan view, the areas of the first and second preliminary line structures 18 a and 18 b exposed by the first mask patterns 51, between the first active region 6 a and the second active region 6 b, may be increased.

Referring to FIGS. 18, 19A, 19B, 19C and 19D, when viewed in a plan view, a second mask pattern 54 having an opening 54 a exposing a partial region between the first active region 6 a and the second active region 6 b may be formed.

The first and second preliminary line structures 38 a and 38 b may be exposed while spaces between the opening 54 a of the second mask pattern 54 and the first mask patterns 51 overlap. Then, the exposed first and second preliminary line structures 38 a and 38 b may be etched to form separation holes 59. For example, forming the separation holes 59 by etching the exposed first and second preliminary line structures 38 a and 38 b may include exposing the gate capping patterns 48 of the first and second preliminary line structures 38 a and 38 b while the spaces between the opening 54 a of the second mask pattern 54 and the first mask patterns 51 overlap, exposing the gate patterns 45 and the gate spacers 25 by etching the gate capping patterns 48, and etching the exposed gate patterns 45 and the gate spacers 25.

In the etching process for forming the separation holes 59, a portion of the gate spacers 25 may remain.

In another example, in the etching process for forming the separation holes 59, the gate spacers 25 may be etched to expose the first device isolation layer 15 a below the gate spacers 25.

Referring again to FIGS. 1 and 2A to 2E, first and second insulating separation patterns 60 a and 60 b filling the separation holes 59 may be formed. The first and second insulating separation patterns 60 a and 60 b may constitute the first line structures 42 a, 60 a, and 42 b and the second line structures 42 c, 60 b and 42 d described above with reference to FIGS. 1 and 2A to 2E. Subsequently, contact plugs 65 a, 65 b, 65 c, 65 d, and 65 e may be formed to penetrate through the interlayer insulating layers 36 and the insulating liner 33.

Forming the contact plugs 65 a, 65 b, 65 c, 65 d and 65 e may include forming contact holes penetrating through at least the interlayer insulating layers 36 and the insulating liner 33 by performing a photo and etching process, filling the contact holes with a conductive material, and performing a planarization process until the gate capping patterns 48 a, 48 b, 48 c and 48 are exposed. By the planarization process, upper surfaces of the gate capping patterns 48 a, 48 b, 48 c, 48, the interlayer insulating layer 36, the first and second insulating separation patterns 60 a and 60 b, and the contact plugs 65 a, 65 b, 65 c, 65 d, and 65 e may be formed at substantially the same height level. In the process of forming contact holes penetrating through at least the interlayer insulating layers 36 and the insulating liner 33, the first mask patterns 51 may prevent the interlayer insulating layers 36 from collapsing or being deformed. Accordingly, in the process of forming the contact plugs 65 a, 65 b, 65 c, 65 d, and 65 e, defects caused by the collapse or deformation of the interlayer insulating layers 36 may be prevented.

According to an etching process for forming the first and second insulating separation patterns 60 a and 60 b or an etching process used to form the contact plugs 65 a, 65 b, 65 c, 65 d, and 65 e, various structures such as those described with reference to FIGS. 3 to 9 may be formed.

As set forth above, according to example embodiments, a method of separating a gate electrode in a line structure extending in one direction, and a semiconductor device formed according to the method, may be provided. For example, to separate the gate electrode, mask patterns extending in the same longitudinal direction as that of the gate electrode are formed on the interlayer insulating layers to prevent the interlayer insulating layers from collapsing or being deformed, and an additional mask having an opening for separating the gate electrode is formed to divide the gate electrode into two gate electrodes. The mask patterns may be formed to have a narrow width in the region where the gate electrode is separated such that the gate spacer in the region where the gate electrode is separated may be etched together. Accordingly, by separating the gate electrode using the mask patterns and the additional mask, a defect caused by the gate electrode not being completely separated may be prevented.

While example embodiments have been illustrated and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the disclosure as defined by the appended claims. 

What is claimed is:
 1. A semiconductor device comprising: a substrate; a first active region and a second active region extending parallel to each other in a first direction, on the substrate; an isolation layer disposed between the first active region and the second active region; a line structure disposed on the substrate, overlapping the first and second active regions and the isolation layer, and extending in a second direction that is perpendicular to the first direction; a first source/drain region disposed on the first active region; a second source/drain region disposed on the second active region; a common contact plug disposed on a first side of the line structure, contacting the first source/drain region and the second source/drain region, and overlapping the isolation layer; and an interlayer insulating layer disposed on a second side of the line structure, on the isolation layer, wherein the line structure is disposed on the isolation layer and between the common contact plug and the interlayer insulating layer, the line structure comprises a first gate structure overlapping the first active region and extending on the isolation layer, a second gate structure overlapping the second active region and extending on the isolation layer, and an insulating separation pattern disposed between the first gate structure and the second gate structure and extending into the isolation layer, at least a portion of the insulating separation pattern is disposed between the common contact plug and the interlayer insulating layer, the insulating separation pattern has a first side surface and a second side surface opposing each other in the first direction, and a third side surface and a fourth side surface opposing each other in the second direction, at least one of the first side surface and the second side surface of the insulating separation pattern comprises a first portion, a second portion on a level lower than the first portion, and a third portion on a level lower than the second portion, and a slope of each of the first portion and the third portion is steeper than a slope of the second portion.
 2. The semiconductor device of claim 1, wherein the first gate structure comprises a first gate pattern, a first gate spacer disposed on one side of the first gate pattern, and a second gate spacer disposed on another side of the first gate pattern, the second gate structure comprises a second gate pattern, a third gate spacer disposed on one side of the second gate pattern, and a fourth gate spacer disposed on another side of the second gate pattern, the first gate pattern comprises a first gate dielectric layer and a first gate electrode disposed on the first gate dielectric layer, the second gate pattern comprises a second gate dielectric layer and a second gate electrode disposed on the second gate dielectric layer, the first gate electrode contacts the first side surface of the insulating separation pattern, and the second gate electrode contacts the second side surface of the insulating separation pattern.
 3. The semiconductor device of claim 2, wherein the line structure further comprises a connection spacer extending between the first gate spacer and the third gate spacer, the first side surface of the insulating separation pattern comprises the first portion, the second portion, and the third portion, and an upper end of the connection spacer contacts the second portion.
 4. The semiconductor device of claim 3, wherein the first side surface of the insulating separation pattern comprises the first portion, the second portion, and the third portion, and the third portion is in contact with the isolation layer.
 5. The semiconductor device of claim 2, wherein the first gate structure further comprises a first insulating capping pattern disposed on the first gate pattern, the second gate structure further comprises a second insulating capping pattern disposed on the second gate pattern, and upper surfaces of the first insulating capping pattern, the insulating separation pattern, the second insulating capping pattern and the interlayer insulating layer are coplanar with each other.
 6. The semiconductor device of claim 5, wherein the first insulating capping pattern covers upper surfaces of the first and second gate spacers, and the second insulating capping pattern covers upper surfaces of the third and fourth gate spacers.
 7. The semiconductor device of claim 1, further comprising an insulating liner covering a lower surface of the interlayer insulating layer, wherein the insulating liner extends from the lower surface of the interlayer insulating layer to cover at least a portion of a side surface of the interlayer insulating layer, and a portion of the insulating liner contacts with the insulating separation pattern.
 8. The semiconductor device of claim 1, wherein the common contact plug comprises a portion extending into the isolation layer, and a lowermost end of the common contact plug is disposed on a level lower than an upper surface of the first active region and an upper surface of the second active region.
 9. The semiconductor device of claim 1, further comprising: an insulating liner disposed between the interlayer insulating layer and the isolation layer.
 10. The semiconductor device of claim 1, wherein, when viewed in a plan view, a side surface of the common contact plug has a concave shape in a region that contacts or is adjacent to the insulating separation pattern of the line structure.
 11. The semiconductor device of claim 1, wherein in a region of the common contact plug overlapping the isolation layer and adjacent to the insulating separation pattern of the line structure, a lower surface of the common contact plug has a convex shape in a direction away from an upper surface of the substrate.
 12. A semiconductor device comprising: a substrate; a first active region and a second active region extending parallel to each other in a first direction, on the substrate; an isolation layer disposed between the first active region and the second active region; a first line structure and a second line structure overlapping the first and second active regions and the isolation layer, and extending parallel to each other in a second direction that is perpendicular to the first direction, on the substrate; a first source/drain region disposed on the first active region; and a second source/drain region disposed on the second active region, wherein the first line structure comprises: a first gate structure overlapping the first active region and extending on the isolation layer, a second gate structure overlapping the second active region and extending on the isolation layer, and a first insulating separation pattern disposed between the first gate structure and the second gate structure and extending into the isolation layer, the second line structure comprises: a third gate structure overlapping the first active region and extending on the isolation layer, a fourth gate structure overlapping the second active region and extending on the isolation layer, and a second insulating separation pattern disposed between the third gate structure and the fourth gate structure and extending into the isolation layer, the first insulating separation pattern and the second insulating separation pattern are spaced apart from each other, the first insulating separation pattern has a first side surface and a second side surface opposing each other in the first direction, and a third side surface and a fourth side surface opposing each other in the second direction, and at least one of the first side surface and the second side surface of the first insulating separation pattern and at least one of the third side surface and the fourth side surface of the first insulating separation pattern have different side profiles.
 13. The semiconductor device of claim 12, wherein at least one of the first side surface and the second side surface of the first insulating separation pattern comprises a first portion, a second portion on a level lower than the first portion, and a third portion on a level lower than the second portion, the third portion is disposed in the isolation layer, the second portion extends from the third portion and has a slope smaller than a slope of the third portion, and the first portion extends from the second portion and has a slope steeper than the slope of the second portion.
 14. The semiconductor device of claim 12, wherein the first gate structure comprises a first gate pattern, a first gate spacer disposed on one side of the first gate pattern, a second gate spacer disposed on another side of the first gate pattern, and a first insulating capping pattern on the first gate pattern and the first and second gate spacers, the second gate structure comprises a second gate pattern, a third gate spacer disposed on one side of the second gate pattern, a fourth gate spacer disposed on another side of the second gate pattern, and a second insulating capping pattern on the second gate pattern and the third and fourth gate spacers, the first gate pattern comprises a first gate dielectric layer and a first gate electrode on the first gate dielectric layer, the second gate pattern comprises a second gate dielectric layer and a second gate electrode on the second gate dielectric layer, the first gate electrode contacts the first side surface of the first insulating separation pattern, and wherein the second gate electrode contacts the second side surface of the first insulating separation pattern.
 15. The semiconductor device of claim 14, wherein the first line structure further comprises a connection spacer extending from the first gate spacer and the second gate spacer, the connection spacer extends from lower regions of the first and second gate spacers, and an upper end of the connection spacer is disposed on a level lower than upper ends of the first and second gate spacers and contacts the first insulating separation pattern.
 16. The semiconductor device of claim 14, further comprising: first channel layers stacked on the first active region and spaced apart from each other in a vertical direction perpendicular to an upper surface of the substrate; and second channel layers stacked on the second active region and spaced apart from each other in the vertical direction, wherein the first gate pattern surrounds each of the first channel layers, the second gate pattern surrounds each of the second channel layers, the first gate dielectric layer comprises a portion disposed between each of the first channel layers and the first gate electrode, and the second gate dielectric layer comprises a portion disposed between each of the second channel layers and the second gate electrode.
 17. A semiconductor device comprising: a substrate; a first active region and a second active region extending parallel to each other in a first direction, on the substrate; an isolation layer disposed between the first active region and the second active region; a plurality of line structures disposed on the substrate, overlapping the first and second active regions and the isolation layer, extending parallel to each other in a second direction perpendicular to the first direction, and spaced apart from each other; a first source/drain region disposed on the first active region; a second source/drain region disposed on the second active region; interlayer insulating layers disposed between adjacent line structures of the plurality of line structures; and a common contact plug, wherein the plurality of line structures comprises a first line structure and a second line structure adjacent to each other and spaced apart from each other, the first line structure comprises: a first gate structure overlapping the first active region and extending on the isolation layer, a second gate structure overlapping the second active region and extending on the isolation layer, and a first insulating separation pattern disposed between the first gate structure and the second gate structure and extending into the isolation layer, the second line structure comprises: a third gate structure overlapping the first active region and extending on the isolation layer, a fourth gate structure overlapping the second active region and extending on the isolation layer, and a second insulating separation pattern disposed between the third gate structure and the fourth gate structure and extending into the isolation layer, the common contact plug comprises a portion contacting the first and second source/drain regions and disposed between the first insulating separation pattern and the second insulating separation pattern, the first insulating separation pattern comprises a first side surface and a second side surface opposing each other in the first direction, and a third side surface and a fourth side surface opposing each other in the second direction, the first side surface of the first insulating separation pattern comprises a first portion, a second portion below the first portion and a third portion below the second portion, the third portion contacts with the isolation layer, the second portion is bent and extended from the first portion in a direction away from a central axis of the first insulating separation pattern, and the first portion is bent and extended from the second portion.
 18. The semiconductor device of claim 17, wherein in the first direction, the first insulating separation pattern comprises a first width portion having a substantially constant first width, a second width portion having a second width less than the first width, and a third width portion having a third width less than the second width, and the first portion of the first side surface is a side surface of the first width portion of the first insulating separation pattern, the second portion of the first side surface is a side surface of the second width portion of the first insulating separation pattern, and the third portion of the first side surface is a side surface of the third width portion of the first insulating separation pattern.
 19. The semiconductor device of claim 17, wherein the first gate structure comprises a first gate pattern, a first gate spacer disposed on one side of the first gate pattern, a second gate spacer disposed on another side of the first gate pattern, and a first insulating capping pattern on the first gate pattern and the first and second gate spacers, the second gate structure comprises a second gate pattern, a third gate spacer disposed on one side of the second gate pattern, a fourth gate spacer disposed on another side of the second gate pattern, and a second insulating capping pattern on the second gate pattern and the third and fourth gate spacers, wherein the first gate pattern comprises a first gate dielectric layer and a first gate electrode disposed on the first gate dielectric layer, the second gate pattern comprises a second gate dielectric layer and a second gate electrode disposed on the second gate dielectric layer, the first gate electrode contacts the first side surface of the first insulating separation pattern, the second gate electrode contacts the second side surface of the first insulating separation pattern, the first line structure further comprises a connection spacer extending between the first gate spacer and the third gate spacer, the connection spacer extends from lower regions of the first and second gate spacers, and an upper end of the connection spacer contacts the first insulating separation pattern and is disposed on a level lower than upper ends of the first and second gate spacers.
 20. The semiconductor device of claim 19, further comprising: first channel layers stacked on the first active region and spaced apart from each other in a vertical direction perpendicular to an upper surface of the substrate; and second channel layers stacked on the second active region and spaced apart from each other in the vertical direction, wherein the first gate pattern surrounds each of the first channel layers, the second gate pattern surrounds each of the second channel layers, the first gate dielectric layer comprises a portion disposed between each of the first channel layers and the first gate electrode, and the second gate dielectric layer comprises a portion disposed between each of the second channel layers and the second gate electrode. 